1 Skippack Pike, Schwenksville, PA 19473
Phone 610.287.9383
Fax 610.287.9237
www.perkiomenwatershed.org
www.facebook.com/perkiomenwatershed
Environmental Education
Watershed Stewardship
Conservation Programs
What is Non-point Source Pollution and how is it Tied to Stormwater?
Non-point source pollution is contamination stemming from many sources, accumulating to
negatively impact stream quality. Non-point source pollutants can be discharged over a wide
land area, from many different locations, and most find their way to a stream through
stormwater. When it rains, stormwater washes substances off the land and carries them into
local streams. Much of this polluted “runoff” enters storm drains, which lead directly to local
waterways commonly used for swimming, fishing or drinking water supplies. Snowmelt and
irrigation have the same effect, carrying pollutants from plowed fields, city streets or suburban
backyards. Sediment, nutrients, organic and toxic substances originating from land-use activities
can all become non-point source pollution, washing into one stream at many different locations.
What we do to the land, we do to the water.
Pollutants
Many sources can contribute to non-point source pollution. Stormwater runoff can contain toxic
chemicals, petroleum products, oil, detergents, nutrients, bacteria, trash, heavy metals and many
other things that can pollute our waterways. Bacteria can come from faulty septic systems or pet
waste, which can also add excess nutrients to our waterways. Yard waste and fertilizers,
especially when used heavily or just before a storm, contribute many more nutrients, like
phosphorus and nitrogen. While these nutrients are good for plant life, in excess, they can
disrupt aquatic habitat. Often, unnaturally large amounts of algae grow in nutrient-rich waters.
When all that algae dies, its decomposition uses a lot of oxygen from the stream, which can
create a “dead zone” where few things can live.
Herbicides and pesticides for agricultural or personal use contribute toxins to our streams.
Sediment is also a major pollutant in waterways, muddying water, preventing fish from
spawning, and generally destroying stream habitat. Sediment can come from improperly
managed construction projects, eroding stream banks, and any land without appropriate plant
cover or other erosion control. All these pollutants make it more difficult and costly to clean
water for drinking, bathing or cleaning. According to the U.S. Environmental Protection
Agency, “non-point source pollution is the leading remaining cause of water quality problems.”
It is clear non-point source pollution negatively affects drinking water quality, recreation,
fisheries and wildlife.
1 Skippack Pike, Schwenksville, PA 19473
Phone 610.287.9383
Fax 610.287.9237
www.perkiomenwatershed.org
www.facebook.com/perkiomenwatershed
Infiltration
Stormwater runoff is increased by human activities through construction, paving, soil
compaction or changes in the vegetation growing on the land. As runoff increases, flooding
often follows because the water is prevented from seeping into the ground as it naturally would.
Like a filter, soil cleans water as it travels underground to springs or wells. Without this
infiltration, groundwater supplies will continue to decrease, creating potential shortages for
individual drinking water wells and public supplies that rely on public wells. Furthermore, the
rush of water that occurs when stormwater does not infiltrate causes more erosion and degrades
stream channels and aquatic habitats.
Solutions
Current stormwater regulations in Pennsylvania are aimed at reducing the impacts of stormwater
runoff, increasing recharge to public and private water supplies, improving stream habitats and
restoring the overall environmental integrity of watersheds. There are ways you can help prevent
polluted stormwater runoff.
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Never dump anything into storm drains or streams.
Check your vehicles for leaks and have any fixed. Recycle your motor oil.
Wash your vehicles at a car wash, where the dirty water is cleaned and recycled instead
of flowing to a storm drain. Wash other things indoors at a sink, so the water can be
treated.
Prevent any litter or lawn clippings from washing into roads with storm drains.
Use fertilizers and other chemicals sparingly and never before it rains. Dispose of
household chemicals properly.
Avoid erosion by planting on any bare soil and raising your mower height. Consider
putting in a rain garden to clean water and increase infiltration, or a rain barrel to hold
back some of that rushing stormwater.
Make sure your septic system is working properly.
Pick up after your pets.
Volunteer for a planting with the Perkiomen Watershed Conservancy to buffer streams
from non-point source pollution.
1 Skippack Pike, Schwenksville, PA 19473
Phone 610.287.9383
Fax 610.287.9237
www.perkiomenwatershed.org
www.facebook.com/perkiomenwatershed
Sediment from eroding stream banks,
like the one pictured here, is one
example of non-point source pollution.
Photo credit: Krista Scheirer
Sources:
https://www.perkiomenwatershed.org/Stormwater/stormwater_management.aspx
http://water.epa.gov/polwaste/nps/whatis.cfm
http://water.epa.gov/polwaste/nps/outreach/upload/after_the_storm.pdf
http://water.epa.gov/polwaste/nps/outreach/upload/epa_nps_bookmark.pdf